Thermo non-conductor.



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. THERMO non connucroa.' APPLICAT-|0N FILED MAR. 7. 1913- RENEWED IAN. 30. |915- Llalg. Patented sep@ 14, 1915.

CARL G. MUENCHrOF ST. PAUL, MINNESOTA.

THERMO NON-CONDUCTOR.

Specification of Letters Patent.

Application led March 7, 1913, Serial No. 752,614. Renewed January 30, 1915. Serial No. 5,305.

To all whom 'it may concern:

Be it Vknown that I, CARL G. MUENCH, a citizen of the United States, residing at St. Paul, in the county of Ramsey and State l of Minnesota, have invented a new and useing ordinary wood pulp as it comes from the cookers and grinders and using the ne pulp for paper and other purposes and the residue of coarse long and short bers for my insulation. In other words I use what is known as pulp screenings or tailings, which is at the present time useless, has no value and is only refuse. By using this waste ma'- .terial'I produce a very inexpensive and eicient non-conducting felt which is more effective and less expensive to produce than any non-conducting material in use, at the 'present time.

' My sheet non-conductor is made by owing a thin mixture of coarse long and shbrt wood bers and water upon an endless moving screen passing under a suitable evener said mixture draining and felting as it travels and passing between progressive l pressing devices which express'moisture and slightly and then drying.

reduce the mixture to a sheet of desired thickness. The sheet is cut into lengths or slabs and the pieces-placed in a kiln to dry.

The blocks or other shapes are made by casting in a form of the desired shape, pressing e sheets or blocks are extremely light, and tough having great tensile strength and containing countless air cells, thus producing an ideal non-conductor having a specic gravity of 'only fteen to twentyv one-hundredths. The l sheets and slabs are also flexible and therefore well adapted for structuralpurposes. My thermal insulation .made of long and short wood bers can also` have a small amount of flax, jute or hemp ber' either singly or together incorporated in it before -felting to give it evenV greater tensile strength without impairing its quality as a non-conductor. A small'vpercentage of ammonium or other salts or other suitable material can be added to the mixture of long and short wood bers and water before feltratentea sept. ifi, isis.

ing to render the nished product uncombustible. By applying a thin coating of hot parain wax, paran oil, wax tailings or the like to my non-conductor before it is placed in the kiln it will berendered water proof. As theI moisture leaves the felt the uid oil or wax is drawn through by capillary attraction so that every ber 'is permeated and water Droofed. v

I am aware that ordinary short ber wood pulp mixed with plaster of Paris, hair, infusorial earth, straw and cork has been proposed for insulation, but this has never been a commercial success. In these mixtures the materials are made into a plastic form and then applied or molded into the desired shape and allowed to dry resulting in a hard rigid 'material with very little tensileV strength. Sheets made of any of these mixtures the size and thickness which are necessary for practical purposes cannot be handled without. breaking and are therefore impracticable. The materials mentioned in these mixtures `are also too expensive for commercial purposes. My thermal insulation is totally different because instead of being molded, it is felte'd, that is the long and short wood bers and water are mixed, so that they are in a thin uid state, and are then vflowed on a screen apron through which the water drains, leaving a thick felted or matted layer of long and short wood bers which when slightly pressed and dried produces a strong tough sheet, which cannot be produced with ordinary wood pulp. In

producing sheets of my improved non-conductor a felting machine is emploved, one form of structure being illustrated in the accompanying drawing which forms part of this specification.

The term long and short wood bers asv used in thisl specication and the claims following is relative in so far as related to wood ber as appearing in the tailings received from a pulp mill, but all of such bers are short as compared with the bers found in ax, jute and hemp or in strips or shavings of material such as have been heretofore used lation to tailings received from a pulp mill.`

In .this drawing, vFigurel is ay longitudinal section of the'machine; Fig. 2 is a cross section of the machine taken on the line X-X of Fig. 1, and Fig. 3 is a detail illustrating part of the driving mechanism.

In this drawing, A represents a screen endless apron, the upper lap of which moves forward over the bed 2, said apron passing around the idle pulley 3, and the drive pulley 4. The upper lap of the belt and the bed of the machine incline upwardly from the idle pulley toward the drive pulley. The lower end of the lap receives a thin solution or mixture of long wood fibers and water from the tank -B, said solution being spread evenly upon the surface of the apron, an evener 5 being employed to assisi'I in spreading the mixture evenly and `said p evener being revolved and said apron driven in the direction of the arrows indicated in Fig. 1. After the wood pulp mixture C advancesI with the apron, the water gradually drains through the apron, the thickness of the mixture radually. reducing as the belt advances. T e upper lap of the apron near its upper end passes between progressive pairs of pressing rollers, D, E and F, which serve' to press the felted or matted layer of long coarse wood fibers step by stepuntil ultimately the liquid in the lap is expressed leavinga sheet of non-conducting material in moist condition, which is ejected from the apron upon a traveling conveyer G, said conveyer carrying the sheet forward over the idle rollers H on to trays such as I. Each'tray I 'is placed on va conveyer `6,

which travels in the direction of the arrows shown in Fig. k1, and serves to move the tray forward so as to catch and conductthe sheet of non-conducting material while it is egressing from the machine. When the successive trays I receive the strip ofnonconducting material, said strip is cut by hand into short lengths or slabs which are carried away by an attendant on the trays and placed in a drying kiln. After the kiln has been lilledwith the loaded trays and-the sheets or slabs of non-conducting material on the trays dried or baked, strong tough sheets orV Aslabs of non-conducting vanced at equal surface speed byany suit-' able mechanism, the drawing illustrating a train of gears J operatedby the drive pulley 7 by which the speed of operation is reduced so that the actuated parts move at very slow speed. At the sides of the upper lap of the belt A,'deckels 10 are -provided which serve as guards, to prevent the mixture when in liuid state from running over the sides of the belt and to produce a sheet of material of even width having smooth regular side edges. Below the apron A, a tank 8 is placed having a drain 9, said tank serving to catch any drip from the apron which is expressed from the pulp mixture.

The term tailings as used inthis speciication and the claims following is intended to include the product'commonly lmown as screenings which are the waste product of a pulp mill.

Having described my invention, what I claim as new and desire to protect by Letters vPatent is 1. A thermal non-conductor composed wood pulp tailings yfelted into a light, spongy sheet, pressed slightly and dried.

2. A thermal nonconductor composed of wood pulp tailings felted into a sheet or other shape, fire proofed, pressed slightly vand dried. Y

A. L. raam, F. G. BRADBURY. 

